How long does nicotine stay in system for diptest?

2-3 days: For most smokers. After a single exposure to tobacco smoke, cotinine can be detected in blood or urine for less than 24 hours, but in an individual smoking 1/2 pack or more per day, 2-3 days is common. It is rarely positive after 5 days. Hair testing can detect cotinine (main metabolite) for months, depending on length of hair. Nicotine is very short-acting and is only present for hours.